3. section-1 association of arbuscular mycorrhizal fungi...
TRANSCRIPT
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3. SECTION-1
Association of arbuscular mycorrhizal fungi (AMF) with commonly
leguminous crops cultivated in Aligarh district (U.P.) – A Survey
3.1 INTRODUCTION
Aligarh is located at 27.88° N latitude and 78.08° E longitude and at an
average elevation of 178 m (587 feet) above sea level in the mid of Doab, the land
between the Ganges and Yamuna rivers. The city is situated at a distance of about 90
miles (140 km) south-east of New Delhi on the Delhi-Howrah rail route.
Aligarh experiences semi-arid and sub-tropical climate with hot dry summers
and intense cold winters. The summer season extends from April to June with average
temperature ranges between 28-33 °C (82-91 °F), maximum temperature reaching up
to 46-47 °C in the month of June. The monsoon starts in late June and continuing till
early October with high humidity levels (53-78 °C). The mean annual rainfall is about
850 mm and more than 85% of the total down pour is delivered during the span of
these three months from June to August while remaining occurs in winters which is
useful for rabi crops. The winter starts from November and ends in March, where
December and January are the coldest months and average temperature ranges
between 13-15 °C whilst the lowest temperature for any single day may go down up
to 1-2 °C.
The total area of Aligarh district is 3696.94 sq. km and it has 82% of the
geographical area under cultivation. The core sector of economy is agriculture and
crops raised in this district include wheat, paddy, pulses, oil seeds, potato, ber and
guava.
Arbuscular mycorrhizal (AM) fungi are ubiquitous and form symbiotic
association with roots of about 90% plants in natural and agricultural ecosystems
(Harley and Smith, 1983; Powell and Bagyaraj, 1984; Gabor, 1991; Brundrett, 2002;
Muthukumar and Prakash, 2009; Mahmood and Rizvi, 2010). The significance of AM
fungi in augmenting food production is increasingly appreciated as these organisms
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can increase plant growth (Smith and Read, 1997), plant reproductive capacity (Lu
and Koide, 1994), plant water stress tolerance (Gupta and Kumar, 2000) and plant
health through antagonisic and competitive effects on pests and pathogens (Gange and
West, 1994). AM fungi are responsible for enhanced uptake of immobile mineral
nutrients especially phosphorus from the soil to the host plants and thereby enhancing
vigor (Gerdemann, 1964; Nicolsan, 1967; Mosse, 1972; Mosse, 1973; Barea et al.,
1988; Wani et al., 1991; Jakobsen, 1999; Akhtar and Siddiqui, 2008; Jalaluddin et al.,
2008; Giasson et al., 2008; Sawers et al., 2008). That is why they are referred as
„biofertilizers‟ and can be substantiated for the substantial amounts of chemical
fertilizers. Despite the importance of mycorrhizae in agriculture and forestry, little
work has been done regarding their distribution, diversity and association with the
host plants in India. The selection of the most appropriate plant-fungus association for
each specific environmental and ecological situation is one of the main challenges in
current research on AM fungi. Therefore, knowledge of different factors influencing
the population biology of AM fungi is essential to use them in sustainable agriculture.
Legumes are important pulse cultivated throughout Indian subcontinent, cost
effective cultivation of this agricultural crops depends on effective symbiotic nitrogen
fixation in their nodules that relies on the rhizobial population of the soil (Postgate,
1982). Mycorrhizal infection has particular value for legumes because nodulation and
symbiotic nitrogen fixation by rhizobia require an adequate phosphorus supply and
restrict root system leads to poor competition for soil phosphorus (Carling et al.,
1978). Arbuscular mycorrhizal (AM) association with different leguminous crops is
currently of great interest because of the important role played by these crops in
restoration of degraded soils and enriching soil fertility (Peoples and Craswell, 1992;
Thomas et al., 1997). Thus the cultivation of leguminous crops is increasing steadily
to maintain a steady supply and to support their increasing demand. But
corresponding research works on the occurrence of AM fungi and their associations in
legumes have received little attention as compared to the studies on forest species.
This has prompted to evaluate the mycorrhizal status of leguminous crops at
Aligarh district. Hence, the present study was undertaken to make a general survey on
mycorrhizal colonization with different leguminous crops and spore population in
rhizosphere soils at twelve blocks of Aligarh district.
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3.2 MATERIALS AND METHODS
3.2.1 Sites selection, soil and crop sampling
A qualitative and quantitative survey of species of distribution of arbuscular
mycorrhizal fungi was carried out at different blocks viz., Atrauli (B1), Akrabad (B2),
Bijauli (B3), Chandaus (B4), Dhanipur (B5), Gangiri (B6), Gonda (B7), Iglas (B8),
Jawan (B9), Khair (B10), Lodha (B11) and Tappal (B12) of Aligarh district of Uttar
Pradesh, India during the year 2008-2009. Six commonly cultivated leguminous crops
viz., pea (Pisum sativum L.), chickpea (Cicer arietinum L.), pigeonpea (Cajanus
cajan L.) Mill sp., mungbean (Vigna radiata L.) Wilczek, cowpea (Vigna unguiculata
L.) Walp., blackgram (Vigna mungo L.) Hepper and lentil (Lens culinaris Medikus)
were selected for study at each site.
Sampling was done for each crop separately from the fields of leguminous
crops at different sites. Soil samples (soil cones of 5 cm diam.) were collected at
random from each site with the help of soil auger upto a depth of 15 cm near the
rhizosphere. Fifty such samples were collected from each plant species and were
thoroughly mixed to make a composite sample. Six samples of 100 g soil were used
for recovery of spores.
Six root samples for each plant species were collected at random in order to
assess root colonization by AM fungi. A representative sample of the entire root
system was obtained from five different portions of the root system after washing by
tap water.
3.2.2 Soil characteristics
During survey, soil characteristics of rhizosphere soil in terms of texture, pH,
electrical conductivity (mmho cm-1
), particle size (%), organic carbon content and
nutrient levels like nitrogen, phosphorus and potassium content of the soil were taken
into considerations to determine the effect of these soil parameters on root
colonization by AM fungi.
The soil samples were brought to laboratory, marked and packed in polythene
bags and their electrical conductivity (EC) and pH were measured with EC meter
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(Rhoades, 1996) and pH meter (Mc Lean, 1982) respectively in 1:1 soil/water
suspension (w/v). The texture of soil in relation to particle size was determined by
hydrometer method (Allen et al., 1974); total organic carbon by Walkey (1947); total
nitrogen by micro-Kjeldahl method (Nelson and Sommers, 1972); total phosphorus by
molybdenum blue method (Allen et al., 1974); and potassium by using flame
photometer (Jackson, 1973).
3.2.3 Isolation of spores from the soil
Mycorrhizal spore count of each soil sample were isolated by a modified wet
sieving and decanting technique (Gerdeman and Nicolson, 1963). Samples of 100 g
dry soil were taken in 1000 ml water, thoroughly shaken and left for a minute to settle
down the heavier particles. The supernatant was poured first through a coarse soil
sieve to remove large piece of organic matter and then decanted on to a series of
varied size sieves i.e., 80, 100, 150, 250 and 400 mesh. Spores obtained on sieves
were collected with water in separate beakers. The spore suspensions were repeatedly
washed by Ringer‟s solution (NaCl - 6 g L-1
, KCl – 0.1 g L-1
and CaCl2 – 0.1 g L-1
in
distilled water of pH 7.4) in order to remove the adhered soil particles from the
spores. The spores were counted in 1ml of the suspension in nematode counting dish
under the stereoscopic microscope. Spore numbers from the three replicates per
samples were averaged and the result was expressed as spore number per 100 g of dry
soil basis. The final number of AM spores of each species per 100 g of soil were
calculated accordingly for each crop.
3.2.4 Identification of AM fungi spores
The isolated spores of AM fungi were identified under a dissecting
microscope with the help of synoptic keys suggested by various workers (Hall and
Fish, 1979; Trappe, 1982; Schenck and Perez, 1987; Rani and Mukerji, 1988; Srinivas
et al., 1988; Raman and Mohankumar, 1988). For species identification, Perez and
Schenck (1990) manual was followed. Different genera were identified on the basis of
sporocarpic and spore characters such as spore size, shape, colour, surface structure,
general nature of the contents, hyphal attachments, spore wall and other
morphological structures (Schenck and Perez, 1990). The spores of different AM
fungal species were separated with a microspatula and picked up by a Pasteur pipette
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fitted with a rubber bulb and then spores were used for pot culture. These tools were
surface sterilized for 2 minutes in a solution containing chloramine T – 20 g L-1
,
streptomycin - 300 mg L-1
and Tween 80 in trace amount mL-1
of distilled water.
3.2.5 Assessment of colonization by AM fungi
Clearing and staining (Phillips and Hayman, 1970)
Roots were washed with tap water and cut into 1 cm long segments and then
boiled in 10% KOH solution at 90 oC for 45 minutes. KOH solution was then poured
off and roots were rinsed well in a beaker until no brown colour appeared in the rinsed
water. Alkaline H2O2 which was used to bleach the roots, was made by adding 3 ml of
NH4OH to 30 ml of 10% H2O2 and 567 ml of tap water. The roots were rinsed
thoroughly at least three times using tap water to remove the H2O2. Roots were then
treated with 0.05% trypan blue (in lactophenol) and were kept for an hour. The
specimens were then removed from trypan blue and kept for overnight in a destaining
solution, prepared with acetic acid (laboratory grade) – 875 ml, glycerine – 63 ml and
distilled water – 63 ml.
The cellular contents were removed by this method and the AM fungal
structures stained dark blue. These stained root segments were used for determining
the root colonization by AM fungi.
The percentage/proportion of root colonization by AM fungi was determined
by the grid line intersecting method (Giovanetti and Mosse, 1980). The root segments
were selected at random from the stained sample and mounted on microscopic slides
in group of ten. One hundred to one hundred and fifty root segments from each
samples were used for the assessment. The presence or absence of colonization in
each root segment was recorded and the per cent root colonization (mycorrhizal
infection in the roots) was calculated as follows:
Number of AM positive segments
% root colonization = –––––––––––––––––––––––––––––––– x 100
Total number of segments screened
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3.2.6 Statistical Analysis
The data collected during this study were statistically analyzed in simple
randomized design by the method of Panse and Sukhatme (1985). All the data were
subjected to Analysis of Variance (ANOVA) to assess the significance of variations in
AM fungal variables among leguminous crop species. Minimum difference required
for significance (C.D.) at P=0.01 and P=0.05 was calculated by the ANOVA model 1
given in Appendix.
3.3 RESULTS
3.3.1 Soil characteristics
It was found that all the sites (B1 to B12) surveyed have sandy loam soil and
their compositions were almost the same with narrow pH range of 7.5 (B2) to 8.9 (B9).
The electrical conductivity was lowest at Akrabad (B2) and highest at Jawan (B9).
Organic carbon content of the soil at block B1 was highest, followed by B12, B8, B4,
B5, B2, B7, B10, B9, B6, B11 and B3 blocks. As far as the soil nutrients are concerned,
nitrogen content was highest at Atrauli (184 kg ha-1
) and phosphorus and potassium
content ranged between 7.54 (B2) to 42.17 (B1) and 102.30 (B3) to 252.60 (B1) kg ha-1
respectively. Soil at Atrauli (B1) has comparatively high N, P & K content than the
soil at other blocks and Chandaus (B4) have the largest area under pulses production
i.e. 2,840 ha (Table 4).
3.3.2 Root colonization and spore population
The data provided in table 5 indicates that the root colonization (%) and total
AMF spore number 100 g-1
of soil varied with the crop as well as with the twelve sites
investigated.
At block B1, arbuscular mycorrhizal colonization was observed in almost all
grain legumes. The highest colonization (60.2%) was observed in chickpea and the
lowest (14.4%) in lentil. Blackgram and lentil showed very poor colonization
compared to other legumes. Results clearly indicated that root colonization diversified
within the members of the same family. Total spore numbers ranged from 155 in
lentil to 227 in chickpea 100 g-1
dry soil. AMF spores 100 g-1
soil was more than 200
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Table 4. Some physico-chemical characteristics of the rhizosphere soil surveyed at twelve blocks in Aligarh district
Different blocks
in Aligarh Soil texture pH
Electrical
conductivity
(mmho cm-1
)
Particle size (%) Organic
carbon
(%)
Available nutrients (kg ha-1
) Area
under
pulses (ha) Sand Silt Clay N P K
Atrauli (B1) Sandy Loam 8.4 5.1 70.3 20.5 9.2 0.30 184 42.17 252.60 1,906
Akrabad (B2) Sandy Loam 7.5 3.8 76.4 17.8 5.8 0.26 160 7.54 205.79 2,247
Bijauli (B3) Sandy Loam 7.7 3.9 74.9 19.1 6.0 0.21 101 7.80 102.30 1,085
Chandaus (B4) Sandy Loam 8.3 4.8 75.6 15.9 8.5 0.27 133 18.00 151.00 2,840
Dhanipur (B5) Sandy Loam 7.9 4.0 77.1 16.4 6.5 0.27 154 12.45 194.26 2,329
Gangiri (B6) Sandy Loam 7.8 3.9 70.7 23.0 6.3 0.23 108 8.11 118.94 2,170
Gonda (B7) Sandy Loam 8.5 5.3 72.3 17.2 10.5 0.26 142 10.57 176.83 1,163
Iglas (B8) Sandy Loam 8.0 4.2 75.2 17.4 7.4 0.28 165 14.55 220.32 1,355
Jawan (B9) Sandy Loam 8.9 5.9 74.5 19.4 12.6 0.24 116 19.35 125.61 3,020
Khair (B10) Sandy Loam 8.7 5.6 71.0 17.7 11.3 0.25 139 15.91 163.52 1,760
Lodha (B11) Sandy Loam 8.0 4.3 71.8 20.2 8.0 0.23 171 17.30 235.10 2,744
Tappal (B12) Sandy Loam 8.1 4.5 69.1 22.6 8.3 0.28 127 9.23 137.44 1,695
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in chickpea, pigeonpea and mungbean and it was more than 100 in pea, cowpea,
blackgram and lentil (Fig. 1a).
At block B2, the level of mycorrhizal colonization varied from 53.0-88.0% in
different leguminous crops, highest being exhibited by chickpea. High percentage of
root colonization was observed in pea, chickpea, pigeonpea, mungbean and cowpea
(Fig. 1a). The spore numbers ranged from 395 (blackgram) to 456 (chickpea) 100 g-1
dry soil.
At block B3, the maximum colonization (85.0%) was observed in pigeonpea
and minimum (50.0%) in blackgram. The spore numbers 100 g-1
dry soil in the
rhizosphere ranged from 366 in blackgram to 435 in pigeonpea. Chickpea and
pigeonpea recorded more than 400 spores 100 g-1
dry soil while pea, mungbean,
cowpea, lentil and blackgram recorded more than 300 spores 100 g-1
dry soil (Fig.
1a).
At block B4, the lowest colonization (23.1%) was found in blackgram and the
highest in chickpea (70.0%). Pigeonpea, mungbean, cowpea and pea also showed
higher root colonization (Fig. 1a). Total spore numbers ranged from 197 (blackgram)
to 260 (chickpea) 100 g-1
dry soil. All the legumes recorded more than 200 spores 100
g-1
dry soil except blackgram.
At block B5, different leguminous crops showed different percentages of root
colonization by AM fungi. Per cent root colonization varied from 35.2-77.1%.
Chickpea, pigeonpea, mungbean and pea exhibited comparatively better performance
than cowpea, lentil and blackgram. The rhizosphere soil contained AM spore number
ranging from 278 in lentil to 327 in chickpea 100 g-1
dry soil. More than 200 spores
100 g-1
dry soil divulged in all the legumes (Fig. 1a).
At block B6, the mycorrhizal colonization was highest (82.1%) in chickpea
and lowest (46.1%) in blackgram. Total spore numbers ranged from 341 in blackgram
to 406 in chickpea 100 g-1
dry soil. AMF spores 100 g-1
soil was more than 300 in all
the leguminous crops (Table 5 and Fig. 1a).
At block B7, the mycorrhizal colonization varied from 39.0-79.0% in different
leguminous crops, highest being exhibited by pigeonpea. High percentage of root
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Table 5. Root colonization and spore population of AM fungi in some leguminous crops surveyed at twelve blocks of Aligarh district
Crops
Atrauli (B1) Akrabad (B2) Bijauli (B3) Chandaus (B4) Dhanipur (B5) Gangiri (B6)
Root
colonization
(%)
Number of
AMF spore
100g-1 soil
Root
colonization
(%)
Number of
AMF spore
100g-1 soil
Root
colonization
(%)
Number of
AMF spore
100g-1 soil
Root
colonization
(%)
Number of
AMF spore
100g-1 soil
Root
colonization
(%)
Number of
AMF spore
100g-1 soil
Root
colonization
(%)
Number of
AMF spore
100g-1 soil
Pea 46.0±2.3 200.0±10.0 78.0±3.9 420.0±21.0 73.0±3.7 389.0±19.4 52.5±2.6 236.0±11.8 63.2±3.2 298.0±14.9 71.0±3.5 363.0±18.1
Chickpea 60.2±3.0 227.0±11.4 88.0±4.4 456.0±22.8 85.0±4.3 435.0±21.8 70.0±3.5 260.0±13.0 77.1±3.9 327.0±16.4 82.1±4.1 406.0±20.3
Pigeonpea 51.0±2.5 214.0±10.7 84.0±4.2 440.0±22.0 82.3±4.1 411.0±20.5 58.0±2.9 253.0±12.6 71.4±3.6 314.0±15.7 79.0±3.9 384.0±19.2
Mungbean 53.1±2.7 221.0±11.1 80.0±4.0 428.0±21.4 78.1±3.9 397.0±19.8 55.0±2.8 248.0±12.4 66.2±3.3 303.0±15.1 75.0±3.8 370.0±18.5
Cowpea 32.0±1.6 186.0±9.3 71.1±3.6 414.0±20.7 67.0±3.3 386.0±19.3 40.0±2.0 221.0±11.1 51.3±2.6 286.0±14.3 64.1±3.2 355.0±17.8
Blackgram 14.4±0.7 155.0±7.8 53.0±2.6 395.0±19.8 50.0±2.5 366.0±18.3 23.1±1.2 197.0±9.8 35.2±1.8 278.0±13.9 46.1±2.3 341.0±17.0
Lentil 19.0±1.0 170.0±8.5 62.0±3.1 404.0±20.2 59.2±3.0 374.0±18.7 29.1±1.5 209.0±10.5 43.0±2.1 284.0±14.2 55.1±2.8 348.0±17.4
C.D. (P=0.05) 3.96 17.82 6.75 NS 6.49 35.46 4.57 20.97 5.49 26.86 6.22 33.03
C.D. (P=0.01) 5.55 24.99 9.46 NS 9.10 49.72 6.40 29.40 7.69 37.66 8.71 46.31
Crops
Gonda (B7) Iglas (B8) Jawan (B9) Khair (B10) Lodha (B11) Tappal (B12)
Root
colonization
(%)
Number of
AMF spore
100g-1 soil
Root
colonization
(%)
Number of
AMF spore
100g-1 soil
Root
colonization
(%)
Number of
AMF spore
100g-1 soil
Root
colonization
(%)
Number of
AMF spore
100g-1 soil
Root
colonization
(%)
Number of
AMF spore
100g-1 soil
Root
colonization
(%)
Number of
AMF spore
100g-1 soil
Pea 65.0±3.3 316.0±15.8 60.0±3.0 281.0±14.0 48.0±2.4 222.0±11.1 57.1±2.9 265.0±13.3 54.0±2.7 247.0±12.4 68.4±3.4 334.0±16.7
Chickpea 79.0±3.9 352.0±17.6 75.0±3.8 310.0±15.5 66.0±3.3 245.0±12.3 73.2±3.7 289.0±14.4 71.0±3.5 270.0±13.5 80.4±4.0 378.0±18.9
Pigeonpea 73.0±3.7 333.0±16.7 69.0±3.5 298.0±14.9 54.0±2.7 232.0±11.6 65.0±3.3 277.0±13.9 63.0±3.2 262.0±13.1 76.1±3.8 362.0±18.1
Mungbean 74.0±3.7 339.0±16.9 62.0±3.1 284.0±14.2 50.0±2.5 230.0±11.5 60.0±3.0 272.0±13.6 64.4±3.2 265.0±13.3 72.1±3.6 345.0±17.3
Cowpea 56.0±2.8 312.0±15.6 49.0±2.5 260.0±13.0 36.0±1.8 205.0±10.3 45.0±2.3 247.0±12.4 42.2±2.1 231.0±11.5 60.0±3.0 330.0±16.5
Blackgram 39.0±1.9 294.0±14.7 31.0±1.5 251.0±12.6 20.0±1.0 178.0±8.9 28.5±1.4 227.0±11.3 25.0±1.3 206.0±10.3 42.3±2.1 318.0±15.9
Lentil 48.3±2.4 301.0±15.1 39.0±1.9 256.0±12.8 23.0±1.2 193.0±9.6 34.1±1.7 235.0±11.8 30.0±1.5 220.0±11.0 52.0±2.6 323.0±16.2
C.D. (P=0.05) 5.78 28.86 5.23 25.03 4.21 19.46 4.98 23.36 4.85 21.93 5.97 30.77
C.D. (P=0.01) 8.11 40.47 7.34 35.10 5.90 27.28 6.99 32.75 6.80 30.74 8.37 43.14
Data mean±SD of five replicates
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Atrauli (B1)
Pea
Chi
ckpe
a
Pigeo
npea
Mun
gbea
n
Cow
pea
Bla
ckgr
amLen
til0
50
100
150
200
250
300
Root colonization (%)
Number of AMF spore 100g-1
soil
Akrabad (B2)
Pea
Chi
ckpe
a
Pigeo
npea
Mun
gbea
n
Cow
pea
Bla
ckgr
amLen
til0
100
200
300
400
500
600
Bijauli (B3)
Pea
Chi
ckpe
a
Pigeo
npea
Mun
gbea
n
Cow
pea
Bla
ckgr
amLen
til0
100
200
300
400
500Chandaus (B4)
Pea
Chi
ckpe
a
Pigeo
npea
Mun
gbea
n
Cow
pea
Bla
ckgr
amLen
til0
50
100
150
200
250
300
Dhanipur (B5)
Crops
Pea
Chi
ckpe
a
Pigeo
npea
Mun
gbea
n
Cow
pea
Bla
ckgr
amLen
til0
100
200
300
400Gangiri (B6)
Crops
Pea
Chi
ckpe
a
Pigeo
npea
Mun
gbea
n
Cow
pea
Bla
ckgr
amLen
til0
100
200
300
400
500
Fig. 1(a) Root colonization and spore population of AM fungi in some
leguminous crops surveyed at twelve blocks of Aligarh district
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colonization was observed in pea, chickpea, pigeonpea, mungbean and cowpea. The
spore numbers ranged from 294 (blackgram) to 352 (pigeonpea) 100 g-1
dry soil
(Table 5 and Fig. 1b).
At block B8, the maximum colonization (75.0%) was observed in chickpea
and minimum (31.0%) in blackgram (Fig. 1b). The spore numbers 100 g-1
dry soil in
the rhizosphere ranged from 251 in blackgram to 310 in chickpea.
At block B9, the lowest colonization (20.0%) was found in lentil and the
highest in chickpea (66.0%). Pigeonpea, mungbean, cowpea and pea also showed
higher root colonization. Total spore numbers ranged from 178 (lentil) to 245
(chickpea) 100 g-1
dry soil (Fig. 1b).
At block B10, per cent root colonization varied from 28.5-73.2%. Chickpea,
pigeonpea, mungbean and pea exhibited comparatively better performance than
cowpea, lentil and blackgram. The rhizosphere soil contained AM spore number
ranging from 227 in blackgram to 289 in chickpea 100 g-1
dry soil (Fig. 1b).
At block B11, the highest colonization (71.0%) was observed in chickpea and
the lowest (25.0%) in blackgram (Fig. 1b). Total spore numbers ranged from 206 in
blackgram to 270 in chickpea 100 g-1
dry soil. AMF spores 100 g-1
soil was more than
200 in all the legumes.
At block B12, the level of mycorrhizal colonization varied from 42.3-80.4% in
different leguminous crops, highest being exhibited by pigeonpea. The spore numbers
ranged from 318 (blackgram) to 378 (pigeonpea) 100 g-1
dry soil (Fig. 1b).
3.3.3 Diversification of AM structure
In the root system, AM fungal structures of the selected leguminous crops
diversified irrespective of legume species (Table 6).
At block B1, 100% legumes had hyphae and 90% had arbuscules. A total of
30% plants produced oval and round shaped vesicles and 10% of plants showed oval
and spherical type of vesicles.
At block B2, all the leguminous crops contained hyphae except lentil and all
crops had arbuscules. Chickpea, pigeonpea, mungbean and lentil had vesicles. The
3
Gonda (B7)
Pea
Chi
ckpe
a
Pigeo
npea
Mun
gbea
n
Cow
pea
Bla
ckgr
amLen
til0
100
200
300
400
Root colonization (%)
Number of AMF spore 100g-1
soil
Iglas (B8)
Pea
Chi
ckpe
a
Pigeo
npea
Mun
gbea
n
Cow
pea
Bla
ckgr
amLen
til0
50
100
150
200
250
300
350
Jawan (B9)
Pea
Chi
ckpe
a
Pigeo
npea
Mun
gbea
n
Cow
pea
Bla
ckgr
amLen
til0
50
100
150
200
250
300Khair (B10)
Pea
Chi
ckpe
a
Pigeo
npea
Mun
gbea
n
Cow
pea
Bla
ckgr
amLen
til0
50
100
150
200
250
300
350
Lodha (B11)
Crops
Pea
Chi
ckpe
a
Pigeo
npea
Mun
gbea
n
Cow
pea
Bla
ckgr
amLen
til0
50
100
150
200
250
300Tappal (B12)
Crops
Pea
Chi
ckpe
a
Pigeo
npea
Mun
gbea
n
Cow
pea
Bla
ckgr
amLen
til0
100
200
300
400
500
Fig. 1(b) Root colonization and spore population of AM fungi in some
leguminous crops surveyed at twelve blocks of Aligarh district
4
shape of vesicles were both oval and spherical in chickpea, pigeonpea and lentil while
mungbean contained round and spherical shaped vesicles.
At block B3, hyphae were found in all the leguminous crops except pigeonpea
and all crops had arbuscules except blackgram. Both arbuscules and vesicles were
found in pigeonpea, mungbean and cowpea. Oval and round shaped vesicles were
displayed in pigeonpea and cowpea while oval and spherical shaped vesicles were
found in mungbean (Table 6).
At block B4, all the leguminous crops contained hyphae and arbuscules except
lentil. Mungbean, cowpea and blackgram contained both arbuscules and vesicles.
Mungbean, cowpea and lentil contained both oval and spherical shaped vesicles. Only
blackgram had spherical shaped vesicle.
At block B5, hyphae were found in all the leguminous crops. Arbuscules were
present in chickpea, pigeonpea, mungbean and cowpea; vesicles were found in
chickpea, pigeonpea and mungbean. The shape of vesicle was oval and spherical in
pigeonpea and mungbean; chickpea had oval and round shaped vesicles.
At block B6, all the leguminous crops contained hyphae and arbuscules. Both
oval and spherical shaped vesicles were present in chickpea and cowpea.
At block B7, all the leguminous crops contained hyphae except lentil. Both
arbuscules and vesicles were found in pigeonpea and cowpea (Table 6). Oval and
round shaped vesicles were displayed in pigeonpea and cowpea while oval and
spherical shaped vesicles were found in lentil.
At block B8, hyphae were present in all the leguminous crops except lentil.
Pigeonpea, mungbean, blackgram and lentil contained both arbuscules and vesicles.
Blackgram had only spherical shaped vesicle; pigeonpea and lentil contained both
oval and spherical shaped vesicles; mungbean had round and spherical shaped
vesicles.
At block B9, all the leguminous crops contained hyphae and arbuscules. Only
mungbean contained oval and spherical shaped vesicles.
1
Table 6. Arsbuscular mycorrhizal structure (hyphae, arbuscules and vesicles) in different leguminous crops surveyed at twelve blocks of Aligarh
district
Crops Atrauli (B1) Akrabad (B2) Bijauli (B3) Chandaus (B4) Dhanipur (B5) Gangiri (B6)
H A V VS H A V VS H A V VS H A V VS H A V VS H A V VS
Pea + + – – + + – – + + – – + + – – + – – – + + – –
Chickpea + + + O, R + + + O, S + + – – + + – – + + + O, R + + + O, S
Pigeonpea + + + O, R + + + O, S – + + O, R + + – – + + + O, S + + – –
Mungbean + + + O, S + + + R, S + + + O, S + + + O, S + + + O, S + + – –
Cowpea + – – – + + – – + + + O, R + + + O, S + + – – + + + O, S
Blackgram + + – – + + – – + – – – + + + S + – – – + + – –
Lentil + + – – – + + O, S + + – – – – + O, S + – – – + + – –
Crops Gonda (B7) Iglas (B8) Jawan (B9) Khair (B10) Lodha (B11) Tappal (B12)
H A V VS H A V VS H A V VS H A V VS H A V VS H A V VS
Pea + + – – + – – – + + – – + – – – + + – – + – – –
Chickpea + + – – + + – – + + – – + + + O, S + + – – + + + O, R
Pigeonpea + + + O, R + + + O, S + + – – + + – – + + – – + + – –
Mungbean + + – – + + + R, S + + + O, S + + + R, S + + + O, S + + – –
Cowpea + + + O, R + – – – + + – – + – – – + + – – + + + O, R
Blackgram + – – – + + + S + + – – + – – – + + – – + + + S
Lentil – – + O, S – + + O, S + + – – + – – – + – – – + + – –
H = Hyphae; A = Arbuscules; V = Vesicle; VS = Vesicle Shape; S = Spherical; O = Oval; R = Round.
1
At block B10, hyphae were found in all the leguminous crops. Arbuscules were
present in chickpea, pigeonpea and mungbean. The shape of vesicles were oval and
spherical and round and spherical in chickpea and mungbean repectively.
At block B11, hyphae were found in all the leguminous crops and all crops had
arbuscules except lentil. Oval and spherical shaped vesicles were displayed in
mungbean only.
At block B12, hyphae were found in all the leguminous crops and all crops had
arbuscules except pea. Chickpea and cowpea contained both oval and round shaped
vesicles. Only blackgram had spherical shaped vesicle (Table 6).
3.3.4 Distribution of AM genera
It was evident from the table 7 (a, b, c, d) and figure 2 that the distribution of
different AM genera in the rhizosphere of selected legume crops diversified
considerably. The rhizosphere soils of various crops represents six AM genera.
The most distributed genera are Glomus, Gigaspora and Acaulospora
followed by Scutellospora, Entrophosphora and Sclerocystis. Glomus, Gigaspora and
Acaulospora were observed abundantly in the rhizosphere soil of almost all
leguminous crops surveyed under twelve blocks. Scutellospora, Entrophosphora and
Sclerocystis were found rarely with a small number of legume crops under all the
blocks (Fig. 2).
This investigation discloses that AM fungi are common in all the legumes
assessed from various blocks. Glomus was the most predominat genus among all the
six genera recorded in this study (Table 7a, b, c, d)
3.3.5 Distribution of AM species
The data provided in table 8 (a, b, c, d) and figure 3 shows the spore number
of different species of the most frequent AM genera surveyed viz., Glomus mosseae,
Glomus constrictum, Glomus fasciculatum, Glomus intraradices, Glomus
aggregatum, Gigaspora gigantea and Acaulospora scrobiculata at different blocks in
relation to different leguminous crops.
1
Table 7a. Distribution of AM genera in the rhizosphere soils of different leguminous crops surveyed at twelve blocks in Aligarh district
Blocks Crops Glomus (%) Gigaspora (%) Acaulospora (%) Scutellospora (%) Entrophosphora (%) Sclerocystis (%) Unidentified
Atrauli (B1) Pea 75.0±3.8 6.0±0.3 4.0±0.2 0.0±0.0 0.0±0.0 0.0±0.0 15.0±0.8
Chickpea 84.0±4.2 6.0±0.3 7.0±0.4 0.0±0.0 0.0±0.0 0.0±0.0 3.0±0.2
Pigeonpea 80.0±4.0 4.0±0.2 0.0±0.0 3.0±0.2 1.0±0.0 0.0±0.0 12.0±0.6
Mungbean 77.0±3.9 8.0±0.4 1.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 14.0±0.7
Cowpea 67.0±3.3 16.0±0.8 8.0±0.4 0.0±0.0 0.0±0.0 0.0±0.0 7.0±0.4
Blackgram 70.0±3.5 9.0±0.5 3.0±0.2 3.0±0.2 0.0±0.0 0.0±0.0 15.0±0.8
Lentil 73.0±3.7 6.0±0.3 10.0±0.5 1.0±0.0 0.0±0.0 0.0±0.0 10.0±0.5
C.D. (P=0.05) 6.79 0.74 0.53 0.14 0.03 0.0±0.0 1.64
C.D. (P=0.01) 9.52 1.04 0.74 0.19 0.05 0.0±0.0 2.30
Akrabad (B2) Pea 55.0±2.8 6.0±0.3 18.0±0.9 4.0±0.2 0.0±0.0 0.0±0.0 17.0±0.8
Chickpea 58.0±2.9 4.0±0.2 20.0±1.0 1.0±0.0 6.0±0.3 0.0±0.0 11.0±0.6
Pigeonpea 57.0±2.8 8.0±0.4 15.0±0.8 8.0±0.4 3.0±0.2 2.0±0.1 7.0±0.4
Mungbean 53.0±2.7 10.0±0.5 23.0±1.2 5.0±0.3 0.0±0.0 0.0±0.0 7.0±0.4
Cowpea 52.0±2.6 8.0±0.4 14.0±0.7 6.0±0.3 0.0±0.0 0.0±0.0 20.0±0.9
Blackgram 50.0±2.5 7.0±0.4 21.0±1.1 2.0±0.1 1.0±0.0 1.0±0.0 18.0±0.9
Lentil 51.0±2.5 11.0±0.6 19.0±1.0 3.0±0.2 2.0±0.1 0.0±0.0 14.0±0.7
C.D. (P=0.05) 4.83 0.67 1.69 0.39 0.25 0.07 1.66
C.D. (P=0.01) 6.77 0.95 2.37 0.55 0.35 0.10 2.33
Bijauli (B3) Pea 50.0±2.5 9.0±0.4 19.0±1.0 8.0±0.4 0.0±0.0 0.0±0.0 14.0±0.7
Chickpea 59.0±2.9 12.0±0.6 16.0±0.8 6.0±0.3 0.0±0.0 0.0±0.0 7.0±0.4
Pigeonpea 58.0±2.9 11.0±0.6 11.0±0.6 7.0±0.4 0.0±0.0 0.0±0.0 13.0±0.7
Mungbean 54.0±2.7 9.0±0.4 20.0±1.0 2.0±0.1 0.0±0.0 0.0±0.0 15.0±0.8
Cowpea 53.0±2.6 13.0±0.7 10.0±0.5 6.0±0.3 0.0±0.0 0.0±0.0 18.0±0.9
Blackgram 52.0±2.6 11.0±0.6 15.0±0.8 5.0±0.3 0.0±0.0 1.0±0.0 16.0±0.8
Lentil 55.0±2.8 10.0±0.5 12.0±0.6 1.0±0.0 1.0±0.0 0.0±0.0 21.0±1.0
C.D. (P=0.05) 4.90 0.97 1.35 0.51 0.03 0.03 1.28
C.D. (P=0.01) 6.87 1.36 1.90 0.71 0.05 0.05 1.80 Data mean±SD of five replicates
2
Table 7b. Distribution of AM genera in the rhizosphere soils of different leguminous crops surveyed at twelve blocks in Aligarh district
Blocks Crops Glomus (%) Gigaspora (%) Acaulospora (%) Scutellospora (%) Entrophosphora (%) Sclerocystis (%) Unidentified
Chandaus (B4) Pea 70.0±3.5 9.0±0.4 5.0±0.3 0.0±0.0 0.0±0.0 0.0±0.0 16.0±0.8
Chickpea 79.0±3.9 6.0±0.3 2.0±0.1 0.0±0.0 1.0±0.0 0.0±0.0 12.0±0.6
Pigeonpea 76.0±3.8 8.0±0.4 2.0±0.1 0.0±0.0 0.0±0.0 0.0±0.0 14.0±0.7
Mungbean 72.0±3.6 8.0±0.4 6.0±0.3 0.0±0.0 0.0±0.0 0.0±0.0 14.0±0.7
Cowpea 69.0±3.5 10.0±0.5 8.0±0.4 1.0±0.0 0.0±0.0 0.0±0.0 12.0±0.6
Blackgram 66.0±3.3 9.0±0.4 7.0±0.4 0.0±0.0 0.0±0.0 0.0±0.0 18.0±0.9
Lentil 71.0±3.5 11.0±0.6 9.0±0.4 0.0±0.0 0.0±0.0 0.0±0.0 9.0±0.4
C.D. (P=0.05) 6.47 0.76 0.50 0.03 0.03 0.0±0.0 1.23
C.D. (P=0.01) 9.07 1.06 0.70 0.05 0.05 0.0±0.0 1.73
Dhanipur (B5) Pea 57.0±2.8 15.0±0.8 11.0±0.6 1.0±0.0 0.0±0.0 0.0±0.0 16.0±0.8
Chickpea 65.0±3.3 16.0±0.8 14.0±0.7 1.0±0.0 0.0±0.0 0.0±0.0 4.0±0.2
Pigeonpea 67.0±3.3 17.0±0.9 12.0±0.6 1.0±0.0 0.0±0.0 0.0±0.0 3.0±0.2
Mungbean 61.0±3.0 14.0±0.7 15.0±0.8 0.0±0.0 0.0±0.0 0.0±0.0 10.0±0.5
Cowpea 55.0±2.8 20.0±1.0 17.0±0.9 0.0±0.0 0.0±0.0 0.0±0.0 8.0±0.4
Blackgram 53.0±2.6 18.0±0.9 17.0±0.9 1.0±0.0 0.0±0.0 0.0±0.0 11.0±0.6
Lentil 57.0±2.8 17.0±0.9 12.0±0.6 1.0±0.0 0.0±0.0 0.0±0.0 13.0±0.7
C.D. (P=0.05) 5.35 1.49 1.26 0.08 0.0±0.0 0.0±0.0 0.84
C.D. (P=0.01) 7.51 2.09 1.77 0.11 0.0±0.0 0.0±0.0 1.18
Gangiri (B6) Pea 54.0±2.7 13.0±0.7 18.0±0.9 3.0±0.2 0.0±0.0 0.0±0.0 12.0±0.6
Chickpea 63.0±3.2 14.0±0.7 16.0±0.8 2.0±0.1 0.0±0.0 0.0±0.0 5.0±0.3
Pigeonpea 65.0±3.3 15.0±0.8 15.0±0.8 3.0±0.2 0.0±0.0 0.0±0.0 2.0±0.1
Mungbean 59.0±2.9 11.0±0.6 10.0±0.5 2.0±0.1 0.0±0.0 0.0±0.0 18.0±0.9
Cowpea 52.0±2.6 18.0±0.9 20.0±1.0 5.0±0.3 0.0±0.0 0.0±0.0 5.0±0.3
Blackgram 50.0±2.5 16.0±0.8 12.0±0.6 3.0±0.2 0.0±0.0 0.0±0.0 19.0±1.0
Lentil 52.0±2.6 14.0±0.7 17.0±0.8 4.0±0.2 0.0±0.0 0.0±0.0 13.0±0.7
C.D. (P=0.05) 5.12 1.29 1.39 0.28 0.0±0.0 0.0±0.0 1.06
C.D. (P=0.01) 7.17 1.81 1.96 0.39 0.0±0.0 0.0±0.0 1.49 Data mean±SD of five replicates
3
Table 7c. Distribution of AM genera in the rhizosphere soils of different leguminous crops surveyed at twelve blocks in Aligarh district
Blocks Crops Glomus (%) Gigaspora (%) Acaulospora (%) Scutellospora (%) Entrophosphora (%) Sclerocystis (%) Unidentified
Gonda (B7) Pea 76.0±3.8 6.0±0.3 2.0±0.1 0.0±0.0 0.0±0.0 0.0±0.0 16.0±0.8
Chickpea 86.0±4.3 7.0±0.4 5.0±0.3 0.0±0.0 0.0±0.0 0.0±0.0 2.0±0.1
Pigeonpea 88.0±4.4 2.0±0.1 1.0±0.0 1.0±0.0 0.0±0.0 0.0±0.0 8.0±0.4
Mungbean 84.0±4.2 9.0±0.4 2.0±0.1 0.0±0.0 0.0±0.0 0.0±0.0 5.0±0.3
Cowpea 71.0±3.5 14.0±0.7 6.0±0.3 0.0±0.0 0.0±0.0 0.0±0.0 9.0±0.5
Blackgram 65.0±3.3 10.0±0.5 4.0±0.2 1.0±0.0 0.0±0.0 0.0±0.0 20.0±1.0
Lentil 74.0±3.7 7.0±0.4 3.0±0.2 0.0±0.0 0.0±0.0 0.0±0.0 16.0±0.8
C.D. (P=0.05) 10.04 0.75 0.34 0.04 0.0±0.0 0.0±0.0 1.06
C.D. (P=0.01) 14.08 1.05 0.48 0.06 0.0±0.0 0.0±0.0 1.49
Iglas (B8) Pea 62.0±3.1 11.0±0.6 8.0±0.4 1.0±0.0 0.0±0.0 0.0±0.0 18.0±0.9
Chickpea 70.0±3.5 10.0±0.5 7.0±0.4 0.0±0.0 0.0±0.0 0.0±0.0 13.0±0.6
Pigeonpea 68.0±3.4 12.0±0.6 5.0±0.3 0.0±0.0 0.0±0.0 0.0±0.0 15.0±0.8
Mungbean 65.0±3.3 11.0±0.6 9.0±0.4 1.0±0.0 0.0±0.0 0.0±0.0 14.0±0.7
Cowpea 57.0±2.8 15.0±0.8 10.0±0.5 0.0±0.0 0.0±0.0 0.0±0.0 17.0±0.9
Blackgram 51.0±2.5 18.0±0.9 16.0±0.8 0.0±0.0 0.0±0.0 0.0±0.0 15.0±0.8
Lentil 54.0±2.7 14.0±0.7 13.0±0.7 0.0±0.0 0.0±0.0 0.0±0.0 19.0±1.0
C.D. (P=0.05) 5.54 1.16 0.90 0.05 0.0±0.0 0.0±0.0 1.39
C.D. (P=0.01) 7.77 1.63 1.27 0.07 0.0±0.0 0.0±0.0 1.94
Jawan (B9) Pea 80.0±4.0 7.0±0.4 1.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 12.0±0.6
Chickpea 90.0±4.5 8.0±0.4 1.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 1.0±0.0
Pigeonpea 88.0±4.4 6.0±0.3 2.0±0.1 0.0±0.0 0.0±0.0 0.0±0.0 3.0±0.2
Mungbean 85.0±4.3 7.0±0.4 4.0±0.2 0.0±0.0 0.0±0.0 0.0±0.0 4.0±0.2
Cowpea 78.0±3.9 8.0±0.4 2.0±0.1 0.0±0.0 0.0±0.0 0.0±0.0 12.0±0.6
Blackgram 73.0±3.7 10.0±0.5 4.0±0.2 0.0±0.0 0.0±0.0 0.0±0.0 13.0±0.7
Lentil 75.0±3.8 11.0±0.6 3.0±0.2 0.0±0.0 0.0±0.0 0.0±0.0 11.0±0.6
C.D. (P=0.05) 7.33 0.74 0.23 0.0±0.0 0.0±0.0 0.0±0.0 0.76
C.D. (P=0.01) 10.28 1.04 0.33 0.0±0.0 0.0±0.0 0.0±0.0 1.07 Data mean±SD of five replicates
4
Table 7d. Distribution of AM genera in the rhizosphere soils of different leguminous crops surveyed at twelve blocks in Aligarh district
Blocks Crops Glomus (%) Gigaspora (%) Acaulospora (%) Scutellospora (%) Entrophosphora (%) Sclerocystis (%) Unidentified
Khair (B10) Pea 78.0±3.9 8.0±0.4 2.0±0.1 0.0±0.0 0.0±0.0 0.0±0.0 12.0±0.6
Chickpea 89.0±4.4 6.0±0.3 4.0±0.2 0.0±0.0 0.0±0.0 0.0±0.0 1.0±0.0
Pigeonpea 87.0±4.4 8.0±0.4 3.0±0.2 0.0±0.0 0.0±0.0 0.0±0.0 2.0±0.1
Mungbean 82.0±4.1 4.0±0.2 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 14.0±0.7
Cowpea 71.0±3.5 7.0±0.4 1.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 21.0±1.1
Blackgram 66.0±3.3 11.0±0.6 5.0±0.3 0.0±0.0 0.0±0.0 0.0±0.0 18.0±0.9
Lentil 75.0±3.8 9.0±0.4 2.0±0.1 0.0±0.0 0.0±0.0 0.0±0.0 14.0±0.7
C.D. (P=0.05) 7.10 0.70 0.27 0.0±0.0 0.0±0.0 0.0±0.0 1.09
C.D. (P=0.01) 9.95 0.98 0.38 0.0±0.0 0.0±0.0 0.0±0.0 1.53
Lodha (B11) Pea 64.0±3.2 12.0±0.6 8.0±0.4 0.0±0.0 0.0±0.0 0.0±0.0 16.0±0.8
Chickpea 71.0±3.5 9.0±0.4 6.0±0.3 0.0±0.0 0.0±0.0 0.0±0.0 14.0±0.7
Pigeonpea 69.0±3.5 13.0±0.7 7.0±0.4 0.0±0.0 0.0±0.0 0.0±0.0 11.0±0.6
Mungbean 68.0±3.4 10.0±0.5 6.0±0.3 0.0±0.0 0.0±0.0 0.0±0.0 16.0±0.8
Cowpea 59.0±2.9 14.0±0.7 9.0±0.5 1.0±0.0 0.0±0.0 0.0±0.0 17.0±0.9
Blackgram 52.0±2.6 20.0±1.0 12.0±0.6 0.0±0.0 0.0±0.0 0.0±0.0 16.0±0.8
Lentil 55.0±2.8 18.0±0.9 15.0±0.8 0.0±0.0 1.0±0.0 0.0±0.0 11.0±0.6
C.D. (P=0.05) 5.67 1.24 0.83 0.03 0.03 0.0±0.0 1.29
C.D. (P=0.01) 7.95 1.74 1.16 0.05 0.05 0.0±0.0 1.81
Tappal (B12) Pea 69.0±3.5 10.0±0.5 7.0±0.4 0.0±0.0 0.0±0.0 0.0±0.0 14.0±0.7
Chickpea 75.0±3.8 11.0±0.6 6.0±0.3 0.0±0.0 0.0±0.0 0.0±0.0 8.0±0.4
Pigeonpea 77.0±3.9 9.0±0.5 4.0±0.2 0.0±0.0 0.0±0.0 0.0±0.0 10.0±0.5
Mungbean 72.0±3.6 12.0±0.6 5.0±0.3 0.0±0.0 0.0±0.0 0.0±0.0 11.0±0.6
Cowpea 66.0±3.3 12.0±0.6 10.0±0.5 0.0±0.0 0.0±0.0 0.0±0.0 12.0±0.6
Blackgram 61.0±3.0 15.0±0.8 11.0±0.6 0.0±0.0 0.0±0.0 0.0±0.0 13.0±0.7
Lentil 68.0±3.4 13.0±0.7 9.0±0.4 0.0±0.0 0.0±0.0 0.0±0.0 10.0±0.5
C.D. (P=0.05) 6.27 1.05 0.68 0.0±0.0 0.0±0.0 0.0±0.0 0.98
C.D. (P=0.01) 8.79 1.47 0.96 0.0±0.0 0.0±0.0 0.0±0.0 1.37 Data mean±SD of five replicates
1
Glo
mu
s (%
)
0
20
40
60
80
100
Gig
asp
ora
(%
)
0
5
10
15
20
25
Aca
ulo
spo
ra (
%)
0
5
10
15
20
25
30
Scu
tell
osp
ora
(%
)
0
2
4
6
8
10
En
tro
ph
osp
ho
ra (
%)
0
1
2
3
4
5
6
7
Scl
ero
cyst
is (
%)
0.0
0.5
1.0
1.5
2.0
2.5
Pea Chickpea Pigeonpea Mungbean Cowpea Blackgram Lentil
Un
iden
tifi
ed
0
5
10
15
20
25
Atrauli (B1)
Akrabad (B2)
Bijauli (B3)
Chandaus (B4)
Dhanipur (B5)
Gangiri (B6)
Gonda (B7)
Iglas (B8)
Jawan (B9)
Khair (B10
)
Lodha (B11
)
Tappal (B12
)
Fig. 2 Distribution of AM genera in the rhizosphere soils of different leguminous
crops surveyed at twelve blocks in Aligarh district
2
At block B1, G. fasciculatum has the highest spore numbers followed by G.
mosseae, G. intraradices G. constrictum, G. aggregatum, Acaulospora scrobiculata
and Gigaspora gigantea, highest being exhibited by chickpea (180, 174, 168, 165,
159, 30 and 28 spores) (Table 8a).
At block B2, the highest spore number was observed by G. fasciculatum in all
the legumes (Table 8a). Gigaspora gigantea has the lowest spore number.
At block B3, G. mosseae has highest spore number than G. fasciculatum in all
the crops. The lowest number of spores were found in Gigaspora gigantean (Table 8a
and Fig. 3).
At block B4, G. fasciculatum has the highest spore numbers as compared to
other AM species. Lowest spore numbers were recorded in Acaulospora scrobiculata
(Table 8b).
At block B5, the highest spore numbers were recorded for G. fasciculatum
followed by G. mosseae, G. constrictum, G. intraradices, G. aggregatum, Gigaspora
gigantea and Acaulospora scrobiculata (Table 8b). At this site, pigeonpea showed
greater number of spores than chickpea.
At block B6, G. fasciculatum showed the highest spore numbers in all the
legumes as compared to other AM species; lowest being recorded in Gigaspora
gigantea. Chickpea and pigeonpea recorded almost similar spore numbers (Table 8b
and Fig. 3).
At block B7, G. mosseae recorded highest spore numbers than G.
fasciculatum. Almost same number of spores were exhibited by pigeonpea and
chickpea (Table 8c).
At block B8, the highest spore number was observed by G. fasciculatum in all
the legumes (Table 8c). Acaulospora scrobiculata has the lowest spore number.
Chickpea showed highest spore number.
At block B9, G. fasciculatum has the highest spore numbers followed by G.
mosseae, G. intraradices G. constrictum, G. aggregatum, Gigaspora gigantea and
Acaulospora scrobiculata, highest being exhibited by chickpea (210, 207, 196, 192,
1
Table 8a. Distribution of AM species in the rhizosphere soils of different leguminous crops surveyed at twelve blocks in Aligarh district
Blocks Crops Glomus
mosseae (Gm)
Glomus
constrictum (Gc)
Glomus
fasciculatum (Gf)
Glomus
intraradices (Gi)
Glomus
aggregatum (Ga)
Gigaspora
gigantea (Gg)
Acaulospora
scrobiculata (As)
Atrauli (B1) Pea 165.0±8.3 152.0±7.6 166.0±8.3 157.0±7.8 143.0±7.2 17.0±0.8 20.0±1.0
Chickpea 174.0±8.7 165.0±8.3 180.0±9.0 168.0±8.4 159.0±7.9 30.0±1.5 28.0±1.4
Pigeonpea 172.0±8.6 160.0±8.0 176.0±8.8 164.0±8.2 153.0±7.6 25.0±1.3 26.0±1.3
Mungbean 166.0±8.3 154.0±7.7 171.0±8.6 159.0±7.9 148.0±7.4 21.0±1.0 23.0±1.2
Cowpea 158.0±7.9 142.0±7.1 162.0±8.1 149.0±7.5 130.0±6.5 12.0±0.6 16.0±0.8
Blackgram 152.0±7.6 133.0±6.6 155.0±7.8 137.0±6.9 127.0±6.4 10.0±0.5 13.0±0.7
Lentil 160.0±8.0 145.0±7.3 164.0±8.2 150.0±7.5 132.0±6.6 15.0±0.8 18.0±0.9
C.D. (P=0.05) NS 13.51 15.04 13.91 12.81 1.85 1.95
C.D. (P=0.01) NS 18.95 21.09 19.50 17.96 2.59 2.73
Akrabad (B2) Pea 101.0±5.0 85.0±4.3 105.0±5.3 92.0±4.6 73.0±3.7 22.0±1.1 48.0±2.4
Chickpea 117.0±5.8 97.0±4.9 121.0±6.1 105.0±5.3 82.0±4.1 30.0±1.5 60.0±3.0
Pigeonpea 112.0±5.6 91.0±4.5 116.0±5.8 100.0±5.0 77.0±3.9 27.0±1.4 53.0±2.6
Mungbean 107.0±5.4 88.0±4.4 110.0±5.5 94.0±4.7 75.0±3.8 25.0±1.3 51.0±2.5
Cowpea 96.0±4.8 83.0±4.1 99.0±5.0 89.0±4.4 70.0±3.5 18.0±0.9 45.0±2.3
Blackgram 85.0±4.3 71.0±3.5 90.0±4.5 76.0±3.8 62.0±3.1 14.0±0.7 40.0±2.0
Lentil 90.0±4.5 77.0±3.9 94.0±4.7 83.0±4.1 64.0±3.2 16.0±0.8 42.0±2.1
C.D. (P=0.05) 9.19 7.65 9.53 8.27 6.50 2.07 4.44
C.D. (P=0.01) 12.88 10.73 13.36 11.60 9.12 2.90 6.23
Bijauli (B3) Pea 107.0±5.4 72.0±3.6 99.0±5.0 80.0±4.0 61.0±3.0 21.0±1.0 30.0±1.5
Chickpea 130.0±6.5 100.0±5.0 125.0±6.3 109.0±5.4 86.0±4.3 45.0±2.3 50.0±2.5
Pigeonpea 128.0±6.4 98.0±4.9 125.0±6.3 105.0±5.3 83.0±4.1 42.0±2.1 47.0±2.4
Mungbean 122.0±6.1 93.0±4.6 118.0±5.9 101.0±5.0 80.0±4.0 37.0±1.9 43.0±2.1
Cowpea 115.0±5.8 81.0±4.1 110.0±5.5 90.0±4.5 66.0±3.3 29.0±1.4 35.0±1.8
Blackgram 111.0±5.5 77.0±3.9 107.0±5.4 86.0±4.3 64.0±3.2 25.0±1.3 32.0±1.6
Lentil 118.0±5.9 85.0±4.3 114.0±5.7 94.0±4.7 69.0±3.5 31.0±1.5 38.0±1.9
C.D.(P=0.05) 10.70 7.89 10.29 8.64 6.66 3.13 3.65
C.D. at 1% 15.00 11.06 14.43 12.11 9.33 4.39 5.12 Data mean±SD of five replicates
2
Table 8b. Distribution of AM species in the rhizosphere soils of different leguminous crops surveyed at twelve blocks in Aligarh district
Crops
Glomus
mosseae (Gm)
Glomus
constrictum (Gc)
Glomus
fasciculatum (Gf)
Glomus
intraradices (Gi)
Glomus
aggregatum (Ga)
Gigaspora
gigantea (Gg)
Acaulospora
scrobiculata (As)
Chandaus (B4) Pea 157.0±7.8 145.0±7.3 162.0±8.1 150.0±7.5 130.0±6.5 32.0±1.6 20.0±1.0
Chickpea 173.0±8.7 161.0±8.0 175.0±8.8 165.0±8.3 154.0±7.7 45.0±2.3 30.0±1.5
Pigeonpea 168.0±8.4 155.0±7.8 170.0±8.5 160.0±8.0 148.0±7.4 41.0±2.0 27.0±1.4
Mungbean 164.0±8.2 152.0±7.6 166.0±8.3 157.0±7.8 140.0±7.0 38.0±1.9 23.0±1.2
Cowpea 155.0±7.8 147.0±7.3 157.0±7.8 150.0±7.5 128.0±6.4 30.0±1.5 17.0±0.9
Blackgram 151.0±7.6 140.0±7.0 154.0±7.7 143.0±7.2 126.0±6.3 26.0±1.3 14.0±0.7
Lentil 160.0±8.0 146.0±7.3 165.0±8.3 152.0±7.6 131.0±6.6 37.0±1.9 21.0±1.0
C.D. (P=0.05) NS NS NS NS 12.37 3.29 2.06
C.D. (P=0.01) NS NS NS NS 17.34 4.61 2.88
Dhanipur (B5) Pea 130.0±6.5 121.0±6.1 133.0±6.6 115.0±5.8 109.0±5.4 44.0±2.2 36.0±1.8
Chickpea 137.0±6.9 130.0±6.5 142.0±7.1 126.0±6.3 118.0±5.9 52.0±2.6 43.0±2.1
Pigeonpea 138.0±6.9 129.0±6.4 145.0±7.3 130.0±6.5 120.0±6.0 54.0±2.7 45.0±2.3
Mungbean 135.0±6.8 125.0±6.3 138.0±6.9 122.0±6.1 116.0±5.8 48.0±2.4 40.0±2.0
Cowpea 122.0±6.1 110.0±5.5 126.0±6.3 98.0±4.9 87.0±4.4 36.0±1.8 31.0±1.5
Blackgram 117.0±5.8 93.0±4.7 121.0±6.1 88.0±4.4 84.0±4.2 33.0±1.7 30.0±1.5
Lentil 129.0±6.4 113.0±5.7 131.0±6.6 106.0±5.3 91.0±4.5 41.0±2.0 34.0±1.7
C.D. (P=0.05) 11.62 10.58 12.00 10.19 9.45 4.05 3.39
C.D. (P=0.01) 16.29 14.83 16.82 14.28 13.25 5.68 4.76
Gangiri (B6) Pea 126.0±6.3 110.0±5.5 130.0±6.5 115.0±5.8 98.0±4.9 41.0±2.0 43.0±2.1
Chickpea 136.0±6.8 125.0±6.3 139.0±6.9 130.0±6.5 117.0±5.8 48.0±2.4 47.0±2.4
Pigeonpea 138.0±6.9 124.0±6.2 141.0±7.0 129.0±6.4 120.0±6.0 50.0±2.5 47.0±2.4
Mungbean 133.0±6.6 117.0±5.8 135.0±6.8 121.0±6.1 102.0±5.1 45.0±2.3 45.0±2.3
Cowpea 124.0±6.2 106.0±5.3 126.0±6.3 110.0±5.5 91.0±4.5 37.0±1.9 40.0±2.0
Blackgram 116.0±5.8 94.0±4.7 120.0±6.0 102.0±5.1 83.0±4.1 30.0±1.5 33.0±1.7
Lentil 120.0±6.0 103.0±5.1 125.0±6.3 111.0±5.6 87.0±4.4 34.0±1.7 38.0±1.9
C.D. (P=0.05) 11.45 10.07 11.74 10.55 9.13 3.74 3.79
C.D. (P=0.01) 16.05 14.11 16.46 14.80 12.80 5.25 5.31 Data mean±SD of five replicates
3
Table 8c. Distribution of AM species in the rhizosphere soils of different leguminous crops surveyed at twelve blocks in Aligarh district
Blocks Crops Glomus
mosseae (Gm)
Glomus
constrictum (Gc)
Glomus
fasciculatum (Gf)
Glomus
intraradices (Gi)
Glomus
aggregatum (Ga)
Gigaspora
gigantea (Gg)
Acaulospora
scrobiculata (As)
Gonda (B7) Pea 188.0±9.4 176.0±8.8 185.0±9.3 181.0±9.0 161.0±8.0 30.0±1.5 15.0±0.8
Chickpea 193.0±9.6 180.0±9.0 191.0±9.5 184.0±9.2 170.0±8.5 35.0±1.8 20.0±1.0
Pigeonpea 195.0±9.8 176.0±8.8 192.0±9.6 186.0±9.3 164.0±8.2 37.0±1.9 21.0±1.1
Mungbean 192.0±9.6 174.0±8.7 187.0±9.4 181.0±9.0 160.0±8.0 33.0±1.7 18.0±0.9
Cowpea 183.0±9.2 165.0±8.3 178.0±8.9 172.0±8.6 153.0±7.6 24.0±1.2 11.0±0.6
Blackgram 180.0±9.0 162.0±8.1 175.0±8.8 166.0±8.3 149.0±7.5 21.0±1.1 9.0±0.5
Lentil 186.0±9.3 170.0±8.5 182.0±9.1 174.0±8.7 158.0±7.9 27.0±1.4 14.0±0.7
C.D. (P=0.05) NS NS NS NS NS 2.73 1.47
C.D. (P=0.01) NS NS NS NS NS 3.83 2.06
Iglas (B8) Pea 133.0±6.6 121.0±6.1 139.0±6.9 126.0±6.3 109.0±5.4 46.0±2.3 27.0±1.4
Chickpea 152.0±7.6 140.0±7.0 154.0±7.7 145.0±7.3 128.0±6.4 55.0±2.8 40.0±2.0
Pigeonpea 146.0±7.3 129.0±6.4 150.0±7.5 134.0±6.7 115.0±5.8 52.0±2.6 36.0±1.8
Mungbean 140.0±7.0 126.0±6.3 144.0±7.2 131.0±6.6 111.0±5.6 49.0±2.5 31.0±1.5
Cowpea 131.0±6.6 116.0±5.8 135.0±6.8 122.0±6.1 105.0±5.3 41.0±2.0 24.0±1.2
Blackgram 125.0±6.3 108.0±5.4 127.0±6.4 113.0±5.7 91.0±4.5 35.0±1.8 17.0±0.9
Lentil 128.0±6.4 114.0±5.7 132.0±6.6 119.0±6.0 98.0±4.9 37.0±1.9 20.0±1.0
C.D. (P=0.05) 12.31 11.04 12.62 11.49 9.83 4.14 2.68
C.D. (P=0.01) 17.26 15.48 17.69 16.11 13.78 5.81 3.75
Jawan (B9) Pea 192.0±9.6 176.0±8.8 196.0±9.8 180.0±9.0 163.0±8.2 14.0±0.7 7.0±0.4
Chickpea 207.0±10.3 192.0±9.6 210.0±10.5 196.0±9.8 184.0±9.2 20.0±1.0 12.0±0.6
Pigeonpea 200.0±10.0 185.0±9.3 205.0±10.3 188.0±9.4 173.0±8.7 17.0±0.9 11.0±0.6
Mungbean 197.0±9.9 180.0±9.0 202.0±10.1 184.0±9.2 170.0±8.5 15.0±0.8 9.0±0.4
Cowpea 186.0±9.3 165.0±8.3 191.0±9.5 172.0±8.6 159.0±7.9 12.0±0.6 5.0±0.3
Blackgram 180.0±9.0 160.0±8.0 184.0±9.2 168.0±8.4 155.0±7.8 7.0±0.4 4.0±0.2
Lentil 183.0±9.2 162.0±8.1 187.0±9.4 170.0±8.5 157.0±7.8 10.0±0.5 5.0±0.3
C.D. (P=0.05) 17.24 15.70 NS 16.16 14.94 1.31 0.76
C.D. (P=0.01) 24.18 22.02 NS 22.66 20.95 1.84 1.07 Data mean±SD of five replicates
4
Table 8d. Distribution of AM species in the rhizosphere soils of different leguminous crops surveyed at twelve blocks in Aligarh district
Blocks Crops Glomus
mosseae (Gm)
Glomus
constrictum (Gc)
Glomus
fasciculatum (Gf)
Glomus
intraradices (Gi)
Glomus
aggregatum (Ga)
Gigaspora
gigantea (Gg)
Acaulospora
scrobiculata (As)
Khair (B10) Pea 182.0±9.1 171.0±8.6 185.0±9.3 176.0±8.8 158.0±7.9 18.0±0.9 7.0±0.4
Chickpea 200.0±10.0 180.0±9.0 202.0±10.1 186.0±9.3 180.0±9.0 28.0±1.4 15.0±0.8
Pigeonpea 191.0±9.5 184.0±9.2 195.0±9.8 181.0±9.0 173.0±8.7 25.0±1.3 11.0±0.6
Mungbean 187.0±9.4 180.0±9.0 190.0±9.5 175.0±8.8 162.0±8.1 20.0±1.0 10.0±0.5
Cowpea 177.0±8.8 170.0±8.5 181.0±9.0 163.0±8.2 149.0±7.5 12.0±0.6 4.0±0.2
Blackgram 175.0±8.8 165.0±8.3 179.0±8.9 160.0±8.0 145.0±7.3 10.0±0.5 3.0±0.2
Lentil 179.0±8.9 172.0±8.6 183.0±9.2 166.0±8.3 151.0±7.6 15.0±0.8 6.0±0.3
C.D. (P=0.05) NS NS NS 15.49 14.44 1.80 0.84
C.D. (P=0.01) NS NS NS 21.71 20.25 2.52 1.18
Lodha (B11) Pea 136.0±6.8 125.0±6.3 140.0±7.0 130.0±6.5 111.0±5.6 48.0±2.4 37.0±1.9
Chickpea 150.0±7.5 137.0±6.9 155.0±7.8 142.0±7.1 130.0±6.5 60.0±3.0 45.0±2.3
Pigeonpea 147.0±7.3 135.0±6.8 152.0±7.6 140.0±7.0 121.0±6.1 54.0±2.7 42.0±2.1
Mungbean 139.0±6.9 126.0±6.3 143.0±7.2 131.0±6.6 118.0±5.9 52.0±2.6 40.0±2.0
Cowpea 134.0±6.7 123.0±6.2 137.0±6.9 128.0±6.4 109.0±5.4 45.0±2.3 35.0±1.8
Blackgram 125.0±6.3 110.0±5.5 129.0±6.4 117.0±5.8 97.0±4.8 39.0±1.9 28.0±1.4
Lentil 130.0±6.5 116.0±5.8 133.0±6.6 120.0±6.0 104.0±5.2 41.0±2.0 32.0±1.6
C.D. (P=0.05) 12.35 11.22 12.72 11.68 10.22 4.45 3.39
C.D. (P=0.01) 17.32 15.73 17.84 16.37 14.33 6.24 4.76
Tappal (B12) Pea 146.0±7.3 131.0±6.6 152.0±7.6 135.0±6.8 120.0±6.0 44.0±2.2 30.0±1.5
Chickpea 156.0±7.8 142.0±7.1 160.0±8.0 147.0±7.3 133.0±6.6 50.0±2.5 41.0±2.0
Pigeonpea 159.0±7.9 148.0±7.4 163.0±8.2 150.0±7.5 135.0±6.8 54.0±2.7 37.0±1.9
Mungbean 151.0±7.6 138.0±6.9 155.0±7.8 143.0±7.2 124.0±6.2 48.0±2.4 35.0±1.8
Cowpea 140.0±7.0 122.0±6.1 144.0±7.2 127.0±6.4 112.0±5.6 37.0±1.9 22.0±1.1
Blackgram 135.0±6.8 120.0±6.0 140.0±7.0 123.0±6.2 110.0±5.5 35.0±1.8 19.0±1.0
Lentil 142.0±7.1 126.0±6.3 148.0±7.4 130.0±6.5 117.0±5.8 40.0±2.0 26.0±1.3
C.D. (P=0.05) 13.19 11.93 13.60 12.28 10.97 4.03 2.85
C.D. (P=0.01) 18.49 16.72 19.07 17.22 15.38 5.65 3.99 Data mean±SD of five replicates
1
Glo
mu
s
mo
ssea
e (G
m)
0
50
100
150
200
250
Glo
mu
s
con
stri
ctu
m (
Gc)
0
50
100
150
200
250
Glo
mu
s
fasc
icu
latu
m (
Gf)
0
50
100
150
200
250
Glo
mu
s
intr
ara
dic
es (
Gi)
0
50
100
150
200
250
Glo
mu
s
ag
gre
ga
tum
(G
a)
0
50
100
150
200
250
Gig
asp
ora
gig
an
tea
(G
g)
0
10
20
30
40
50
60
70
Pea Chickpea Pigeonpea Mungbean Cowpea Blackgram Lentil
Aca
ulo
spo
ra
scro
bic
ula
ta (
As)
0
10
20
30
40
50
60
70
Atrauli (B1)
Akrabad (B2)
Bijauli (B3)
Chandaus (B4)
Dhanipur (B5)
Gangiri (B6)
Gonda (B7)
Iglas (B8)
Jawan (B9)
Khair (B10
)
Lodha (B11
)
Tappal (B12
)
Fig. 3 Distribution of AM species in the rhizosphere soils of different leguminous
crops surveyed at twelve blocks in Aligarh district
2
184, 20 and 12 spores). This block recorded highest number of spores as compared to
other blocks surveyed (Table 8c and Fig. 3).
At block B10, the highest spore numbers were recorded for G. fasciculatum
followed by G. mosseae, G. constrictum, G. intraradices, G. aggregatum, Gigaspora
gigantea and Acaulospora scrobiculata (Table 8d).
At block B11, the highest spore numbers recovered were G. fasciculatum in all
the legumes as compared to other AM species and the lowest were Acaulospora
scrobiculata (Table 8d and Fig. 3)
At block B12, G. fasciculatum showed the highest spore numbers and
Acaulospora scrobiculata the lowest. At this site, pigeonpea showed greater number
of spores than chickpea (Table 8d).
3.4 DISCUSSION
The occurrence of arbuscular mycorrhizal fungi in relation to soil
characteristics has been studied by a number of workers (Rovira et al., 1983; Abbott
and Robson, 1985; Meyer and Linderman, 1986; Muthukumar et al., 1996; Bhardwaj
et al., 1997; Siddiqui and Mahmood, 1998; Ananthakrishnan et al., 2004; Molla and
Solaiman, 2009; Nasrullah et al., 2010; Chatterjee et al., 2010; Muthukumar and
Tamilselvi, 2010). The result obtained in the present study show that all the crops
investigated are mycorrhizal in nature, as reported by Mosse (1977) and all the crops
are colonized by AM fungi to a great extent (Tables 2-5).
In the present study, it has been observed that all the crops investigated are
colonized by the different species of AM fungi extensively showing the direct
relationship with spore number prevailing at the site. The data further indicates that
the AM fungal species prefer chickpea and pigeonpea to a greater extent compared to
other leguminous crops investigated.
Results clearly indicate a high percentage of root colonization in chickpea,
pigeonpea, mungbean and pea. Root colonization was detected at all the blocks and
ranged from 14.4% (B1) to 88.0% (B2). High root colonization could be attributed to
low soil phosphorus and optimum moisture condition. Due to the different structure of
root system, the colonization rate of AM fungi might be changed among different
3
plant species in the same site (Hetrick et al., 1992). Chickpea exhibited highest AM
root colonization. Solaiman et al. (2005) and Khanam et al. (2006) reported 70 and
68% colonization in chickpea. The diversities of root colonization in grain legumes
were observed in respect of differences in the structure of the root system and the
amounts of sugars and amino acids in the root exudates (St. John et al., 1981; Hetrick
et al., 1992; Isobe and Tsuboki, 1998; Khanam et al., 2004).
Leguminous crops exhibited a high degree of root colonization by AM fungi.
Low P content of plants could correlate with a decrease in phospholipid levels under
low phosphorus nutrition and an increase in root membrane permeability would
favour mycorrhizal colonization (Graham et al., 1981). Nodulating legumes generally
require a large amount of phosphorus for optimum growth, nodulation and nitrogen
fixation (Hayman, 1986). In spite of having less extensive root systems, legumes are
able to fulfill their nutritional requirements depending on colonization by native AM
fungi (Bethlenfalvay and Newton, 1991). Solaiman et al. (2005) and Khanam et al.
(2005) reported that AM colonization and spore population were increased in
leguminous crops.
Soil nitrogen is significantly correlated with soil K. However, soil phosphorus
is negatively correlated with root colonization. The role of K in root colonization and
spore numbers of AM fungi is little known as compared to P & N. Potassium has
previously been reported to have no effect on AM fungi (Daniels and Trappe, 1980).
Legume crops occupied higher number of spores. Similar findings were
observed by Khalil et al. (1992), Khanam et al. (2004), Solaiman et al. (2005) and
Lakshman et al. (2010) in Jawa, Bangladesh and Karnataka soils respectively. Highest
spore population 100 g-1
dry soil was recovered in the rhizosphere soil at B1 (155) and
lowest at B2 (456). The variation in spore population at different sites might be due to
biotic and abiotic components of the soil ecosystem and the associating plant species
(Bethlenfalvay and Linderman, 1992). The agricultural significance of the above root
colonization percentage and spore number indicate more nutrient uptake by the
legume crops specially orthophosphates, zinc and copper.
The presence of hyphae, vesicles and arbuscules characterized the
endomycorrhizal colonization. The formation of arbuscules is influenced by the stage
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of plant development and is short-lived structure (Neeraj et al., 1991). During active
vegetative growth, arbuscules are normally formed because of the availability of new
cortical cells and high nutrient requirement by the host. Arbuscules formation
decrease and vesicles formation increase at flowering and fruiting stages (Mosse et
al., 1981). The formation of AM structure was inconsistent and fluctuating from site
to site in the present study. Round, oval and spherical vesicles were observed in the
present study. Similar observations were noted by Khanam et al. (2003, 2004, 2006),
Khanam (2007) and Molla and Solaiman (2009).
A multiple infection has been observed at all the twelve blocks in the present
study. Diversity of spore types has been found to be very high and AM fungal
chlamydospores are quite common in all the samples. Results of similar kind have
been reported by Mosse (1973), Hayman and Stovold (1979) and Khalil et al. (1992).
5 fungal genera viz., Glomus, Gigaspora, Acaulospora, Scutellospora and
Entrophosphora were isolated from the study sites. Out of these, Glomus, Gigaspora,
and Acaulospora were found in all the soils sample of all the blocks of Aligarh
district. Glomus species (G. fasciculatum, G. mosseae, G. constrictum, G. intraradices
and G. aggregatum) were most abundant in the rhizosphere indicatives of their broad
host range. In the present study, the spores of Glomus sporulated abundantly
regardless of legume species and sites. Padmavathi et al. (1991) have also come
across spores of different AM fungi occurring often in agricultural soils and found
that Glomus was the predominant genus among the AM fungi, in addition to
Acaulospora and Gigaspora. It has been further found that the colonization varies to
different levels at different sites. A similar situation has been reported by Sulochana
and Manoharachary (1990), Peng and Shen (1990) and Blaszkowski (1993).
Slightly alkaline soils favoured occurrence of Glomus followed by Gigaspora,
Acaulospora and Scutellospora. These reports are in agreement with Mosse et al.
(1981) who exhibited that a neutral to slightly alkaline soil favoured the
predominance of Glomus and acidic soil allowed Acaulospora. Glomus was
predominant in all the soils which indicated that the dominance of particular genus is
not dependent on the soil pH. These results were supported by Bhardwaj et al. (1997).
AM fungi are wide spread in occurrence and due to their potential for crop
improvement they have been investigated extensively (Powell and Bagyaraj, 1982;
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Mukerji and Dixon, 1992; Mukerji, 1995). The natural occurrence of arbuscular
mycorrhizal fungi in the soils was affected by soil ecological and environmental
factors of physical, chemical and biological nature (Bagyaraj, 1991). Natural
occurrence and predominance of Glomus, Gigaspora and Acaulospora in the
cultivated soils at all the twelve blocks indicates that there is a need of maintaining
them in cultivated soils through proper management. They may be utilized as
biofertilizer and also as biocontrol agents.
3.5 CONCLUSION
Among the 7 leguminous crops surveyed at twelve blocks of Aligarh district,
chickpea and pigeonpea were found highly mycotrophic. Lentil and blackgram
showed poor mycorrhizal colonization. Glomus was the most common genus of AM
fungi with five common species (Glomus mosseae, Glomus constrictum, Glomus
fasciculatum, Glomus intraradices, Glomus aggregatum) followed by Gigaspora
gigantea and Acaulospora scrobiculata while Sclerocystis was the least prevalent
genus in the rhizosphere soil.
3.6 SUMMARY
1. A study was conducted to assess the arbuscular mycorrhizal fungal (AMF)
spore population and per cent root colonization in different leguminous crops
viz., pea, chickpea, pigeonpea, cowpea, mungbean and lentil at twelve blocks
of Aligarh district.
2. Legumes are mycorrhizal at all the sites. Highest root colonization and AMF
spore population was found at block B2 (Akrabad) and lowest at B1 (Atrauli).
3. The percentage colonization and average spore number occurred to the
maximum under chickpea cultivation at all the sites yielding an average of
76%.
4. Mixed population with great diversity in AM fungi spore types and presence
of arbuscules inside the roots were observed.
5. At all the blocks surveyed, three genera of AM fungi, Glomus, Gigaspora and
Acaulospora were identified.
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6. Out of the three, Glomus was the most predominat genus which showed
highest frequency of occurrence at all the blocks investigated.
7. There was no specification between cultivated crops and the AM fungi, as the
spore number in soil collected from rhizosphere of the plants in different crops
varied at different sites. AM fungi preferred chickpea and pigeonpea crop
compared to others as evidenced by rich colonization of these crops at all sites.
8. The results of this study emphasize the need to assess the status of arbuscular
mycorrhizal association in leguminous crops from different micro-ecosystem
to understand their mycorrhizal status.